This invention relates to vehicles and particularly to an axle suspension system for vehicles having air or coil supported rigid axles guided in the longitudinal and transverse directions of the vhicle by means of a closed frame stabilizer pivotally connected for rotation about the transverse axis of the vehicle, to the body and to the axle of the vehicle.
An axle suspension system of this generic category is disclosed in DT-OS 2,241,203, where guidance of the axle in the transverse direction of the vehicle is achieved by providing a shoulder at each bearing point of the closed frame stabilizer to transfer lateral forces to the frame and the rear axle through suitable bearing sleeves or brackets. One of the disadvantages inherent in this suspension system is that at the part of the frame where the bending stresses are at a maximum, the cross section of the frame members is subject to great stress and the durability of the stabilizer is thus impaired accordingly. Said publication alternatively proposes to make the bearings of the frame stabilizer spherical.
Although the type of axle suspension system disclosed in said publication represents an intriguingly simple solution, it has not found general acceptance. Since manufacture of a frame stabilizer having the shoulders needed to absorb lateral forces involves prohibitive cost. Nor has the alternative version using spherical rubber bearings in lieu of the shouldered pivotal or cylindrical bearings gained recognition, for the reason that with this version, one bearing each is subjected not only to tensile and compressive stresses in the transverse and longitudinal directions but additionally also to torsional stresses in two planes, whereby an unacceptably short useful life of said spherical rubber bearings results.